Mail drivers: Separate definition from validation

src/Mail/DriverInterface.php

@@ -10,6 +10,8 @@
 namespace Flarum\Mail;
 
 use Flarum\Settings\SettingsRepositoryInterface;
+use Illuminate\Contracts\Validation\Factory;
+use Illuminate\Support\MessageBag;
 use Swift_Transport;
 
 /**
@@ -31,6 +33,26 @@ interface DriverInterface
      */
     public function availableSettings(): array;
 
+    /**
+     * Ensure the given settings are enough to send emails.
+     *
+     * This method is responsible for determining whether the user-provided
+     * values stored in Flarum's settings are "valid" as far as a simple
+     * inspection of these values can determine it. Of course, this does not
+     * mean that the mail server or API will actually accept e.g. credentials.
+     *
+     * Any errors must be wrapped in a {@see \Illuminate\Support\MessageBag}.
+     * If there are no errors, an empty instance can be returned. In the
+     * presence of validation problems with the configured mail driver, Flarum
+     * will fall back to its no-op {@see \Flarum\Mail\NullDriver}.
+     */
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag;
+
+    /**
+     * Does this driver actually send out emails?
+     */
+    public function canSend(): bool;
+
     /**
      * Build a mail transport based on Flarum's current settings.
      */

src/Mail/LogDriver.php

@@ -10,7 +10,9 @@
 namespace Flarum\Mail;
 
 use Flarum\Settings\SettingsRepositoryInterface;
+use Illuminate\Contracts\Validation\Factory;
 use Illuminate\Mail\Transport\LogTransport;
+use Illuminate\Support\MessageBag;
 use Psr\Log\LoggerInterface;
 use Swift_Transport;
 
@@ -31,6 +33,16 @@ class LogDriver implements DriverInterface
         return [];
     }
 
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag
+    {
+        return new MessageBag;
+    }
+
+    public function canSend(): bool
+    {
+        return false;
+    }
+
     public function buildTransport(SettingsRepositoryInterface $settings): Swift_Transport
     {
         return new LogTransport($this->logger);

src/Mail/MailServiceProvider.php

@@ -9,10 +9,11 @@
 
 namespace Flarum\Mail;
 
-use Flarum\Forum\ValidateMailConfiguration;
 use Flarum\Foundation\AbstractServiceProvider;
 use Flarum\Settings\SettingsRepositoryInterface;
+use Illuminate\Contracts\Validation\Factory;
 use Illuminate\Mail\Mailer;
+use Illuminate\Support\Arr;
 use Swift_Mailer;
 
 class MailServiceProvider extends AbstractServiceProvider
@@ -31,11 +32,29 @@ class MailServiceProvider extends AbstractServiceProvider
         });
 
         $this->app->singleton('mail.driver', function () {
-            return $this->app->make(ValidateMailConfiguration::class)->getWorkingDriver();
+            $configured = $this->app->make('flarum.mail.configured_driver');
+            $settings = $this->app->make(SettingsRepositoryInterface::class);
+            $validator = $this->app->make(Factory::class);
+
+            return $configured->validate($settings, $validator)->any()
+                ? $this->app->make(NullDriver::class)
+                : $configured;
         });
 
         $this->app->alias('mail.driver', DriverInterface::class);
 
+        $this->app->singleton('flarum.mail.configured_driver', function () {
+            $drivers = $this->app->make('mail.supported_drivers');
+            $settings = $this->app->make(SettingsRepositoryInterface::class);
+            $driverName = $settings->get('mail_driver');
+
+            $driverClass = Arr::get($drivers, $driverName);
+
+            return $driverClass
+                ? $this->app->make($driverClass)
+                : $this->app->make(NullDriver::class);
+        });
+
         $this->app->singleton('swift.mailer', function ($app) {
             return new Swift_Mailer(
                 $app->make('mail.driver')->buildTransport(

src/Mail/MailgunDriver.php

@@ -11,7 +11,9 @@ namespace Flarum\Mail;
 
 use Flarum\Settings\SettingsRepositoryInterface;
 use GuzzleHttp\Client;
+use Illuminate\Contracts\Validation\Factory;
 use Illuminate\Mail\Transport\MailgunTransport;
+use Illuminate\Support\MessageBag;
 use Swift_Transport;
 
 class MailgunDriver implements DriverInterface
@@ -19,11 +21,29 @@ class MailgunDriver implements DriverInterface
     public function availableSettings(): array
     {
         return [
-            'mail_mailgun_secret' => 'required', // the secret key
-            'mail_mailgun_domain' => 'required|regex:/^(?!\-)(?:[a-zA-Z\d\-]{0,62}[a-zA-Z\d]\.){1,126}(?!\d+)[a-zA-Z\d]{1,63}$/', // the API base URL
+            'mail_mailgun_secret' => '', // the secret key
+            'mail_mailgun_domain' => '', // the API base URL
+            'mail_mailgun_region' => [ // region's endpoint
+                'api.mailgun.net' => 'US',
+                'api.eu.mailgun.net' => 'EU',
+            ],
         ];
     }
 
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag
+    {
+        return $validator->make($settings->all(), [
+            'mail_mailgun_secret' => 'required',
+            'mail_mailgun_domain' => 'required|regex:/^(?!\-)(?:[a-zA-Z\d\-]{0,62}[a-zA-Z\d]\.){1,126}(?!\d+)[a-zA-Z\d]{1,63}$/',
+            'mail_mailgun_region' => 'required|in:api.mailgun.net,api.eu.mailgun.net',
+        ])->errors();
+    }
+
+    public function canSend(): bool
+    {
+        return true;
+    }
+
     public function buildTransport(SettingsRepositoryInterface $settings): Swift_Transport
     {
         return new MailgunTransport(

src/Mail/MandrillDriver.php

@@ -11,7 +11,9 @@ namespace Flarum\Mail;
 
 use Flarum\Settings\SettingsRepositoryInterface;
 use GuzzleHttp\Client;
+use Illuminate\Contracts\Validation\Factory;
 use Illuminate\Mail\Transport\MandrillTransport;
+use Illuminate\Support\MessageBag;
 use Swift_Transport;
 
 class MandrillDriver implements DriverInterface
@@ -19,10 +21,22 @@ class MandrillDriver implements DriverInterface
     public function availableSettings(): array
     {
         return [
-            'mail_mandrill_secret' => 'required',
+            'mail_mandrill_secret' => '',
         ];
     }
 
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag
+    {
+        return $validator->make($settings->all(), [
+            'mail_mandrill_secret' => 'required',
+        ])->errors();
+    }
+
+    public function canSend(): bool
+    {
+        return true;
+    }
+
     public function buildTransport(SettingsRepositoryInterface $settings): Swift_Transport
     {
         return new MandrillTransport(

src/Mail/NullDriver.php

@@ -10,6 +10,8 @@
 namespace Flarum\Mail;
 
 use Flarum\Settings\SettingsRepositoryInterface;
+use Illuminate\Contracts\Validation\Factory;
+use Illuminate\Support\MessageBag;
 use Swift_NullTransport;
 use Swift_Transport;
 
@@ -20,6 +22,16 @@ class NullDriver implements DriverInterface
         return [];
     }
 
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag
+    {
+        return new MessageBag;
+    }
+
+    public function canSend(): bool
+    {
+        return false;
+    }
+
     public function buildTransport(SettingsRepositoryInterface $settings): Swift_Transport
     {
         return new Swift_NullTransport();

src/Mail/SendmailDriver.php

@@ -10,6 +10,8 @@
 namespace Flarum\Mail;
 
 use Flarum\Settings\SettingsRepositoryInterface;
+use Illuminate\Contracts\Validation\Factory;
+use Illuminate\Support\MessageBag;
 use Swift_SendmailTransport;
 use Swift_Transport;
 
@@ -20,6 +22,16 @@ class SendmailDriver implements DriverInterface
         return [];
     }
 
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag
+    {
+        return new MessageBag;
+    }
+
+    public function canSend(): bool
+    {
+        return true;
+    }
+
     public function buildTransport(SettingsRepositoryInterface $settings): Swift_Transport
     {
         return new Swift_SendmailTransport;

src/Mail/SesDriver.php

@@ -11,7 +11,9 @@ namespace Flarum\Mail;
 
 use Aws\Ses\SesClient;
 use Flarum\Settings\SettingsRepositoryInterface;
+use Illuminate\Contracts\Validation\Factory;
 use Illuminate\Mail\Transport\SesTransport;
+use Illuminate\Support\MessageBag;
 use Swift_Transport;
 
 class SesDriver implements DriverInterface
@@ -19,10 +21,24 @@ class SesDriver implements DriverInterface
     public function availableSettings(): array
     {
         return [
+            'mail_ses_key' => '',
+            'mail_ses_secret' => '',
+            'mail_ses_region' => '',
+        ];
+    }
+
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag
+    {
+        return $validator->make($settings->all(), [
             'mail_ses_key' => 'required',
             'mail_ses_secret' => 'required',
             'mail_ses_region' => 'required',
-        ];
+        ])->errors();
+    }
+
+    public function canSend(): bool
+    {
+        return true;
     }
 
     public function buildTransport(SettingsRepositoryInterface $settings): Swift_Transport

src/Mail/SmtpDriver.php

@@ -10,6 +10,8 @@
 namespace Flarum\Mail;
 
 use Flarum\Settings\SettingsRepositoryInterface;
+use Illuminate\Contracts\Validation\Factory;
+use Illuminate\Support\MessageBag;
 use Swift_SmtpTransport;
 use Swift_Transport;
 
@@ -18,12 +20,28 @@ class SmtpDriver implements DriverInterface
     public function availableSettings(): array
     {
         return [
-            'mail_host' => 'required', // a hostname, IPv4 address or IPv6 wrapped in []
-            'mail_port' => 'nullable|integer', // a number, defaults to 25
-            'mail_encryption' => 'nullable|in:tls,ssl', // "tls" or "ssl"
+            'mail_host' => '', // a hostname, IPv4 address or IPv6 wrapped in []
+            'mail_port' => '', // a number, defaults to 25
+            'mail_encryption' => '', // "tls" or "ssl"
+            'mail_username' => '',
+            'mail_password' => '',
+        ];
+    }
+
+    public function validate(SettingsRepositoryInterface $settings, Factory $validator): MessageBag
+    {
+        return $validator->make($settings->all(), [
+            'mail_host' => 'required',
+            'mail_port' => 'nullable|integer',
+            'mail_encryption' => 'nullable|in:tls,ssl',
             'mail_username' => 'required',
             'mail_password' => 'required',
-        ];
+        ])->errors();
+    }
+
+    public function canSend(): bool
+    {
+        return true;
     }
 
     public function buildTransport(SettingsRepositoryInterface $settings): Swift_Transport